package com.hmdp.service.impl;

import cn.hutool.core.bean.BeanUtil;
import com.hmdp.dto.Result;
import com.hmdp.entity.VoucherOrder;
import com.hmdp.mapper.VoucherOrderMapper;
import com.hmdp.service.ISeckillVoucherService;
import com.hmdp.service.IVoucherOrderService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.utils.RedisIdWorker;
import com.hmdp.utils.UserHolder;
import lombok.extern.slf4j.Slf4j;
import org.redisson.api.RLock;
import org.redisson.api.RedissonClient;
import org.springframework.aop.framework.AopContext;
import org.springframework.core.io.ClassPathResource;
import org.springframework.data.redis.connection.stream.*;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.script.DefaultRedisScript;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import javax.annotation.PostConstruct;
import javax.annotation.Resource;
import java.time.Duration;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Slf4j
@Service
public class VoucherOrderServiceImpl extends ServiceImpl<VoucherOrderMapper, VoucherOrder> implements IVoucherOrderService {

    @Resource
    private ISeckillVoucherService seckillVoucherService;

    @Resource
    private RedisIdWorker redisIdWorker;

    @Resource
    private StringRedisTemplate stringRedisTemplate;

    @Resource
    private RedissonClient redissonClient;

    private static final DefaultRedisScript<Long> SECKILL_SCRIPT;
    static{
        SECKILL_SCRIPT = new DefaultRedisScript<>();
        SECKILL_SCRIPT.setLocation(new ClassPathResource("seckill.lua"));
        SECKILL_SCRIPT.setResultType(Long.class);
    }

    private static final ExecutorService SECKILL_ORDER_EXECUTOR = Executors.newSingleThreadExecutor();

    private BlockingQueue<VoucherOrder> orderTasks = new ArrayBlockingQueue<VoucherOrder>(1024 * 1024 );
    @PostConstruct
    private void init(){
        SECKILL_ORDER_EXECUTOR.submit(new VoucherOrderHandler());
    }

    private class VoucherOrderHandler implements Runnable{

        String queueName = "stream.orders";

        @Override
        public void run() {
            while(true){
                try {
                    //1.获取队列中的订单信息
                    List<MapRecord<String, Object, Object>> list = stringRedisTemplate.opsForStream().read(
                            Consumer.from("g1", "c1"),
                            StreamReadOptions.empty().count(1).block(Duration.ofSeconds(2)),
                            StreamOffset.create(queueName, ReadOffset.lastConsumed())
                    );
                    //2. 判断获取是否成功
                    if (list == null || list.isEmpty()){
                    //2.1 获取失败,说明没有消息,继续下一次循环
                        continue;
                    }
                    //解析消息中的订单信息
                    MapRecord<String, Object, Object> record = list.get(0);
                    Map<Object, Object> value = record.getValue();
                    VoucherOrder voucherOrder = BeanUtil.fillBeanWithMap(value, new VoucherOrder(), true);

                    //3. 获取成功,可以下单
                    handleVoucherOrder(voucherOrder);
                    //4. ACK确认
                    stringRedisTemplate.opsForStream().acknowledge(queueName,"g1",record.getId());
                } catch (Exception e) {
                    log.error("处理订单异常",e);
                    handlePendingList();
                }

            }
        }

        private void handlePendingList() {
            while(true){
                try {
                    //1.获取pending-list的订单信息
                    List<MapRecord<String, Object, Object>> list = stringRedisTemplate.opsForStream().read(
                            Consumer.from("g1", "c1"),
                            StreamReadOptions.empty().count(1),
                            StreamOffset.create(queueName, ReadOffset.from("0"))
                    );
                    //2. 判断获取是否成功
                    if (list == null || list.isEmpty()){
                        //2.1 获取失败,说明pending-list没有异常消息,结束循环
                        break;
                    }
                    //解析消息中的订单信息
                    MapRecord<String, Object, Object> record = list.get(0);
                    Map<Object, Object> value = record.getValue();
                    VoucherOrder voucherOrder = BeanUtil.fillBeanWithMap(value, new VoucherOrder(), true);

                    //3. 获取成功,可以下单
                    handleVoucherOrder(voucherOrder);
                    //4. ACK确认
                    stringRedisTemplate.opsForStream().acknowledge(queueName,"g1",record.getId());
                } catch (Exception e) {
                    log.error("处理pending-list订单异常",e);
                    try {
                        Thread.sleep(20);
                    } catch (InterruptedException ex) {
                        throw new RuntimeException(ex);
                    }
                }

            }
        }
    }
//    private BlockingQueue<VoucherOrder> orderTasks = new ArrayBlockingQueue<VoucherOrder>(1024 * 1024 );
//    @PostConstruct
//    private void init(){
//        SECKILL_ORDER_EXECUTOR.submit(new VoucherOrderHandler());
//    }
//
//    private class VoucherOrderHandler implements Runnable{
//
//        @Override
//        public void run() {
//            while(true){
//                try {
//                    //1.获取队列中的订单信息
//                    VoucherOrder voucherOrder = orderTasks.take();
//
//                    //2.创建订单
//                    handleVoucherOrder(voucherOrder);
//                } catch (Exception e) {
//                    log.error("处理订单异常",e);
//                }
//
//            }
//        }
//    }

    private void handleVoucherOrder(VoucherOrder voucherOrder) {
        //1.获取用户
        Long userId = voucherOrder.getUserId();
        //2.创建锁的对象
        RLock lock = redissonClient.getLock("lock:order:" + userId);
        //3.获取锁
        boolean isLock = lock.tryLock();
        //4.获取锁是否成功
        if (!isLock) {
            //获取锁失败,返回错误信息
            log.error("不允许重复下单");
            return;
        }

        try {
            //获取代理对象(事务)
            proxy.createVoucherOrder(voucherOrder);
        } finally {
            lock.unlock();
        }
    }

    private IVoucherOrderService proxy;

    @Override
    public Result seckillVoucher(Long voucherId) {
        //获取用户
        Long userId = UserHolder.getUser().getId();
        //获取订单id
        Long orderId = redisIdWorker.nextId("order");
        //1. 执行lua脚本
        Long result = stringRedisTemplate.execute(
                SECKILL_SCRIPT,
                Collections.emptyList(),
                voucherId.toString(), userId.toString(), String.valueOf(orderId)

        );
        int r = result.intValue();
        //2. 判断返回值是否为0
        if (r != 0){
            //2.1 不为0
            return Result.fail(r==1 ? "库存不足" : "不能重复下单");
        }
        //3.获取代理对象
        proxy = (IVoucherOrderService) AopContext.currentProxy();
        //3. 返回订单信息
        return Result.ok(orderId);

    }
//    @Override
//    public Result seckillVoucher(Long voucherId) {
//        //获取用户
//        Long userId = UserHolder.getUser().getId();
//
//        //1. 执行lua脚本
//        Long result = stringRedisTemplate.execute(
//                SECKILL_SCRIPT,
//                Collections.emptyList(),
//                voucherId.toString(), userId.toString()
//
//        );
//        int r = result.intValue();
//        //2. 判断返回值是否为0
//        if (r != 0){
//            //2.1 不为0
//            return Result.fail(r==1 ? "库存不足" : "不能重复下单");
//        }
//        VoucherOrder voucherOrder = new VoucherOrder();
//        //2.2 订单id
//        Long orderId = redisIdWorker.nextId("order");
//
//        voucherOrder.setId(orderId);
//        //2.4 用户id
//        voucherOrder.setUserId(userId);
//        //2.5 代金券id
//        voucherOrder.setVoucherId(voucherId);
//        //2.6 放入阻塞队列
//        orderTasks.add(voucherOrder);
//        //3.获取代理对象
//        proxy = (IVoucherOrderService) AopContext.currentProxy();
//        //3. 返回订单信息
//        return Result.ok(orderId);
//
//    }

//    @Override
//    public Result seckillVoucher(Long voucherId) {
//        //1. 查询优惠券
//        SeckillVoucher voucher = seckillVoucherService.getById(voucherId);
//        //2. 判断秒杀是否开始
//        if (voucher.getBeginTime().isAfter(LocalDateTime.now())) {
//            //没开始
//            return Result.fail("秒杀未开始");
//        }
//        //3. 判断秒杀是否结束
//        if (voucher.getEndTime().isBefore(LocalDateTime.now())) {
//            //已结束
//            return Result.fail("秒杀已结束");
//        }
//        //4. 判断库存是否充足
//        if (voucher.getStock() < 1) {
//            //库存不足
//            return Result.fail("库存不足");
//        }
//
//
//        Long userid = UserHolder.getUser().getId();
//        //创建锁的对象
////        SimpleRedisLock lock = new SimpleRedisLock("order" + userid, stringRedisTemplate);
//        RLock lock = redissonClient.getLock("lock:order:" + userid);
//        //获取锁
//        boolean isLock = lock.tryLock();
//        if (!isLock) {
//            //获取锁失败,返回错误信息
//            return Result.fail("不允许重复下单");
//        }
//
//        try {
//            //获取代理对象(事务)
//            IVoucherOrderService proxy = (IVoucherOrderService) AopContext.currentProxy();
//            return proxy.createVoucherOrder(voucherId);
//        } finally {
//            lock.unlock();
//        }
//
//    }


    @Transactional
    public void createVoucherOrder(VoucherOrder voucherOrder) {
        //6. 一人一单
        Long userId = voucherOrder.getUserId();

            //6.1 查询订单
            int count = query().eq("user_id", userId).eq("voucher_id", voucherOrder.getVoucherId()).count();
            //6.2 判断用户是否存在
            if (count > 0) {
                //用户已经购买过了
                log.error("用户已经购买过一次!");
                return;
            }


            // 扣减库存
            boolean success =  seckillVoucherService.update()
                    .setSql("stock = stock - 1")
                    .eq("voucher_id", voucherOrder.getVoucherId()).gt("stock", 0)
                    .update();
            if (!success) {
                log.error("库存不足");
                return;
            }

        //7. 创建订单
            save(voucherOrder);
        }
}
